# Calculating LT1 and LT2 approximately without a blood test? **URL:** \ **Category:** Training\ **Tags:** polarized\ **Created:** [March 15, 2021, 8:57pm UTC](https://www.trainerroad.com/forum/t/calculating-lt1-and-lt2-approximately-without-a-blood-test/55533 "2021-03-15T20:57:15Z")\ **Posts on this page:** 1\ **Showing post:** 138
**Author:** ![DarthShivious](https://sea2.discourse-cdn.com/trainerroad/forum/user_avatar/www.trainerroad.com/darthshivious/32/3182_2.png) [@DarthShivious](https://www.trainerroad.com/forum/u/DarthShivious)\ **Post date:** [January 15, 2022, 5:43pm UTC](https://www.trainerroad.com/forum/t/calculating-lt1-and-lt2-approximately-without-a-blood-test/55533/138 "2022-01-15T17:43:37Z")
> [@Rizzi](#): > > But more than 2 hours on the trainer gets pretty uncomfortable for me. I’m not sure if those 1:45 sessions this pre season have been enough any more… > Now (before starting into extensive then intensive phases again) I’m doing a VO2max block at the moment…maybe unconventional order but want to mix things up and see how the outcomes will differ. Ditto and Ditto. I don’t have the mental focus to spend more than about 90 min on the trainer any longer. I used to do 2-3 hours but had race goals in mind. As much as I think my riding in spring would benefit from a bunch more Z2 / LT1 during winter, just not doing it right now. I think it was Eric @ Zwift in a podcast suggesting that he aims to keep things interesting so folks will accumulate time and do indoor sessions. But for this discussion, if we think we need XYZ hours for physiology but the brain only wants to do 50% of XYZ then its a standoff. Request - Would you report back down the road on if adding that VO2max block seemed to help or hurt? Realize it will be anecdote but I’ve been wondering about kicking off a season with a VO2max block then going into aerobic and then finishing off with a peaking or polishing block. While I do not have an A-Race, I generally take a couple weeks of mountain biking in early fall and will “peak” for that in order to enjoy it as much as possible. This is a good thread! --- _[View the full topic](https://www.trainerroad.com/forum/t/calculating-lt1-and-lt2-approximately-without-a-blood-test/55533)._